Molding apparatus



Marh 12,1935. P .ROLFF 1,994,Q2s.

' MOLDING APPARATUS original Filed Dec. `15. 195o l Patented Mar. 12', 1935 PATENT OFFICE Y l APPARATUS' Friedrich Rol, `Berlin-Frohnau, Germany, as# signor to The'Osborn Manufacturing Company,

. Cleveland, Ohio, VaV corporation of Ohio 1 .l ApplicationDecember 15, 1930,'Serial No. 502,524.

Renewed December 20, 1932. In Germany De- `f cember 16,1929

' c claims. (o1. 22436)- f The present invention'concerns'l a new method andfnew means `Vforthe filling of mold boxes or core boxesfwithl mold'substances such as sand and the like, by pneumatic action.

V Meid machines' in which unecmoidiniling` Substance,"usuallysand, is forced' from a sand cham- ".berinto the core box or mold box by compressed lair' have Suleredirequently from the defect `of `runeven blowing. Too much airf gets into theA 1 0 mold boxiorcorel boxlwth too little mold' sand.

It is known, in ordermto remedy' this defi-zet,V to press the mold sand in the sand chamber before blowing, but this has given riseV tothe diiiculty that the air,- when nrst applied, could not force .15' its way throughthe'sand.` After the air pressure `had 'been applied long enoughto move the sand,

the result was' objectionable in that the-.sand

' was notv all blownlo'ut', but craters formed inthe sand in the chamber in spite of the previous com- 20.`pressicn, 'and these craters enlarged, releasing the pressure above the sand, sonthat the sand chamber was not entirely emptied and thel mold box or core box was not properly and completely lfilled. 251'A Mechanical means `have also been used for driving the mold lling'material, but in the present'invention mechanical means 'are used. solely "to keep the material properly 'conditioned 'for' pneumatic propulsion, the flowofthe material byguide bearings128 and-'29'. The cover-'30- of the 30 pneumatic cylinder 4 has aninlet131 for com-.f`

being .caused solely by .the action of the compressed air.

In the" accompanying drawing the invention is shown by way of example:

Fig. 1 isa front elevation showing the arrangement ofA components ofthe mold machine. Fig, 2 vistheplan of Fig. 1.

Fig. 3 is a section through the moldsubstance 1 struction, the' piecesA ofvwhich can be clamped to- V'container alongy yL1A-b of Fig. 1.

Fig. 4 is' a section through the cylinder head of i the rising vand falling cover,.accordingto c and d basejl. In` the presentembodiment such means i Fig. 5 shows theoperating valve in cros's section 'jpiston rods 41, the pistons 42 of which move in' through e and f rof Fig. 2.

A1 denotes the base of the mold machine. On y' this base 1, columns 2 and 3, are firmly supported in a vertical position. The upper ends of the two columns are connected with each oth'erby a bridge 5, whiohnthe middle is shaped into the air cylinder 4. I In the centre of the column, the 50 moldsubstance container -6 is mounted so as to be vertically movable by the aid of theguide arms 7 and 8. Y

The mold substance container 6 is held at a given height vbytwo compression springs 9 and ,10'

slippedon'to. the column, and engaging beneath the guide arms 7 and 8. The mold substance 1 container 6 isclosed at bottom by a-bottom .11.

In this bottom' outlet` openings 12 for the mold vsubstance are provided The upper opening of the mold substance container is during the work 5 i of molding closed by a coverv 13 which .can rise and fall. The cover 13 is guided in the cylinder head 4 by the aid of a piston 14 and the hollow piston rod 15. The cover 13 has a passage 16 for compressed air.' Compressed air from a control 10 valve 17 `is ledfto this passage 16 by a pipe 18,the

vupper portion of which is flexible. In the'interior of the mold agent container 6, a means for stirring the mold sand is provided.V This means vfor stirringvthe sand `consists mainly of 15 agitator arms 19 which are fixed on a shaft 20.V The shaft 20 passes through the hollow piston rod 15 ofthe cover and-thus through the cylinder 4, and is coupled at Ythe upper endwith .au worm wheel 22.l The worm wheel 22 is connected 20 movement of the oontainer, -the upper end 'of the 25 Lfshaft 20 is journalled in ayoke 25. This'yoke 25 is carried by the upper' ends of two vertical rods 2 6 andl 27 xedly mountedy on the container. These rods 26 and 27 are guided inf the *bridge1 5 getherlby suitable means -such as 37,`adjustable in .height on a post v38 (Fig. 2) rising from the 4G consist of 'screw-adjustable jaws 39-carried by cylinders 40. A compressed air duct 43jconnectied with the controlling valve 17, carries com- 45 pressed air into the cylinders'v of the clampa'nd'f` drives the gripping jaws against the faces' of the mold box. The body 17 of the valve 17 is rota'tablejin its casing by a handwheel 51. -The body v 17' is hollow and is Vclosed except for 'four'l ports. 50

Air is supplied vto'the interior of thevalve by a 'circumferential groove V50and ay port 50 con- 'neoted therewith, the groove being" positioned 'opposite the outlet of a compressed airl supply ypipe 50.V vBy turning the valvebody 17 vairis successively admitted through ports 44, 45 and 46 to pipes 43, 32 and 18, respectively; first setting the clamp 37 to hold the core or mold closed and in place; next moving the piston 14 down to close the cover 13 on the mold substance container; and finally admitting compressed air into the top of the container 6 to blow the core. When the valve is in the position of Fig. 5, sand is being blown from the container 6 into a core or mold. The valve position of Fig. 5 does not correspond to the positions of the various parts in Figs. 1 and 4. u

To stop blowing and open the machine, the valve body 17 is rotated in the opposite direction; thus rst cutting off the airsupply fromthe pipe 18, and at the same time venting that pipe (and through it the container 6) through the channel 49 on the outer surface of the `valve body 17'; second, venting the pipe 32 through the .channel 48 `and so permitting the lid 13 to be lifted by hand or otherwise; third, venting the pipe 45 `and so releasing the clamp 37. h For` filling the mold substance container 6 a mold substance carrier 52 is fitted on the column 2 of the molding machine so that it can be swung away from the machine by means of the bearing'53. In the mold substance container 6, there is inserted 4a part, 54 expanding conically downwards, above which the mold substance is by the aid of the compressed air made dense and compact towards .the outlet openings 12 of the bottom l1, before the mold substance is forcedvout of its container. The above described molding machine which serves as a constructional example of the present invention, works in the following wayzy In the first place, the mold substance container 6, which is mounted so as to be movable up and down on columns 2 and 3 of the basel, is preferably completely filled with sand. This is done by means of the mold substance carrier 52, mounted so as to be pivoted` about the column 2 of the base 1. The valve 17 controllingthe machine isnow turned by means of the hand-wheel 51 fastened to it. Compressed aii1 is fed through the pneumatic duct 50to. the control lvalve The control valve 17 distributes this compressed air fed in and in the iirst place delivers it to the clamp 37 mounted on the base 1, in orderto grip .together at the sides the mold box 36, which is beneath the mold substance container 6. A further actuation of the controlling valve 17 supplies compressedair above the piston 14whereby the Acover 13 is pressed down onto the edge of the mold substance container, the latter being shut off at the top and at the same time moved `vertically until the bottom of the mold substance containerrests on the upper edge of the mold box and in this way also shuts off the upper Vface Yof the mold box. The controlling valve is then vturned further so that compressed air isalso conducted through the rising and falling cover 13, into the mold substance .container 6. Simultaneously with this supply of compressed air into the mold substance container the agitator provided inthe latter container is set in motion by thevelectric motor, so that now the compressed `air,.by the aid of the agitator, continuously forces ,u the mold substance conducted along over the outlet openings of the container bottom, through such openings into the adjoining mold or core boxes. When the mold box is iilled, the controllling-valve is again actuated, whereby the screw clamp is discharged of air and the mold box released at thesides. The air is then released from the upper part of the cylinder 4 whereupon the cover 13 goes upwards and the mold substance container is pressed upwards by the force of the two pressure springs 9 and 10. The mold box is therefore now also released in the vertical gripping direction and can be run out of the machine on the roller-mounted table. By proportioning the speed of rotation and the design of the agitator provided in the mold substance container it is possible as will be immediately understood, to determine the density of the mold substance in the container in such manner that the compressed airacting on the mold substance is notable to penetrate the latter but chiey exercises a surface pressure.

It will be seen from the foregoing that the machine iscapable of making either cores or molds, accordingto whether ,a core box or a mold flask is placed on the table 35. It is contemplated that cores will be the more usual product. Accordingly, inthe specification and claims the terms mold, molding, etc., are to VVbe interpreted soas to include and apply rto cores and core" making as well'as to molds, mold'iiask and core box are used interchangeably, and'so on, it being understood'that a core is a specific instance" a bottom provided with openingsv and also having `a stirring element arranged `to` moveon the bottom and over and across theH openings andmeans to direct compressed air downwardly through the said container so that' such compressed'air'acts on the upper surface of the sandin the 4container and causes the 'sand to be discharged therefrom into the core box through said'openings'together with vcompressed airwhile the sand is being kept in motion by the 'stirring element.

2. A molding machine as claimed in claim `1,

[including means to raise and lower the sand'container and also 'including fiuid'pressure actuated means'to permit the stirring element to be also raised' and lowered. A

3. A molding machine' as rclaimed inclaim 1,

includingmeans to raise and lower the sand containerand also, including iiuid pressure 'actuated means'to permit the stirringelement to Vbe'also raised and lowered and Vcomprising vertical'guides on which the sand container is mounted, a cylinder mounted on said vertical guides,`apistonA inA said cylinder, acover for the sandcontainer movablev and carried by said piston, means to supply compressed air to the cylinder above the 'piston and means connected to the cover of the sand container to discharge compressedair"l into ,the sand container and in which the stirringl element is revoluble in the sand container' andhas a vertical shaft extending up through the cover of the containerv and through the cylinder-and piston. h Y

4. A core or mold blowing machine comprising, in combination, a pressure-tight sand container, a top therefor, means for moving said top axially relatively thereto, an agitator in said container,

and driving means for saidV agitator external tov ',finigsitherein too small to permit flow of jmolding sand byits ownweght, `means belowy said'con" tainer for clamping a core box or mold flask against the bottom thereof, a rotor in said container, an axial shaft for said rotor, a top for said container movable along said shaft, a flexible air pressure connection to said top, a piston above said container for moving said top, and means for rotating said shaft.

6. In a molding machine, means to hold a core box, a. sand container above the core box having a bottom provided with openings and also having a stirring element arranged to move closely adjacent the bottom and over and across the openings and means to direct compressed airdown- Wardly through the said container so that such compressed air acts on the upper surface of the sand in the container and causes the sand to be discharged therefrom into the core box through said openings together with compressed air while the sand is being kept in motion by the stirring element. f

FRIEDRICH ROIFF. 

